The objectives of the study are as follows: (a) Determine the effects of protein-caloric undernutrition on human fetal body, organ and cellular structure. (b) Determine if there are relationships between fetal body and organ abnormalities associated with undernutrition and myelination & cell growth in specific parts of the central nervous system. (c) Determine if there are interrelationships between the aforementioned undernutrition and: (1) maternal disorders during pregnancy (2) various disorders in the fetus (3) various disorders in the liveborn neonate including hypothermia. (d) Determine the interrelationships of a large variety of maternal environmental and demographic factors and undernutrition on fetal body composition and fetal and neonatal disorders. (e) Determine the effects of gestational dietary supplements on the outcome of pregnancy including fetal growth, maternal, fetal and neonatal disorders. (f) Determine the effects of various levels of gestational nutrition on specific defense mechanisms against bacterial infection in the mothers and neonates.